A standard for formatting documents includes portable document format (PDF), a page description language used by, for example, the Adobe Acrobat program. Formatting a document as a PDF file means that the document can be transmitted, such as through attachment to an e-mail, without a loss of formatting of the information in the document. Using a PDF viewer, a recipient of the document can open and view the document, and it will have the same format as when transmitted. In comparison, when a document is transmitted in a format according to a word processing program, some of the formatting can be lost or altered. Therefore, conversion of documents to PDF files preserves the original formatting.
Certain types of document compression methods, however, are not supported by the current PDF or the Adobe Acrobat program. Those types of compression include Mixed Raster Content (MRC) compound image compression, an International Telecommunication Union T.44 standard. MRC compression uses three layers: a text layer, a color layer, and a non-text layer. Each of the three layers is independently and individually compressed. The Adobe Acrobat program and the latest PDF 1.3 only support two layers of compression and, therefore, cannot open and display those documents formatted with MRC compression or other compression methods using more than two layers. The use of the three layer compression serves a valuable purpose in reducing the amount of storage required for documents while still maintaining a particular image quality along with color information for the document. It would be useful to have a document formatting scheme that maintains color information for a document and has compatibility with standard formatting for compressing the document.